Hyponatremia in Cirrhosis

Abstract

Hyponatremia is a relatively common complication of cirrhosis in which there is kidney impairment in the capacity to eliminate solute-free water. This causes disproportionate water retention in relation to the retention of sodium, thus causing a reduction in serum sodium concentration and hypoosmolality. The main pathogenic factor responsible for hyponatremia is a nonosmotic hypersecretion of arginine vasopressin (AVP or antidiuretic hormone) from the neurohypophysis related to circulatory dysfunction. Hyponatremia in cirrhosis is associated with increased morbidity and mortality. The current standard of care based on fluid restriction to 1.5 L/day is rarely effective. Other approaches such as albumin infusion and the use of vaptans, which act by antagonizing specifically the effects of AVP on the V2 receptors located in the kidney tubules, have been evaluated for their role in the management of hyponatremia. Short-term treatment with vaptans is associated with a marked increase in renal solute-free water excretion and improvement of hyponatremia; however, their use in patients with end-stage liver disease is limited by hepatoxic effects of some of these drugs. This chapter discusses the evaluation and management of patients with cirrhosis and ascites.